Lake Maurepas is an oligohaline lake in southeastern Louisiana, USA that lies on the western end of the Lake Pontchartrain basin. While Lake Pontchartrain has been studied extensively, there is a relative lack of information regarding the organismal diversity in Lake Maurepas, especially in regards to its invertebrate assemblages. The primary purpose of this study is to characterize the spatial and temporal variability in the macroinvertebrate assemblage in Lake Maurepas using environmental DNA (eDNA). We are sampling the lake every three months to assess temporal and spatial variability in the assemblages. So far, we have collected water and soil samples from two seasons (winter and spring) from inshore and offshore sites. Our samples have been extracted and PCR amplification of a 313 bp fragment of the cytochrome oxidase I gene (mtDNA) is underway. To date, we have cultivated a reference library of invertebrates collected from Lake Maurepas and have Sanger sequenced them. We are preparing eDNA samples for Illumina sequencing and development of our analytical pipeline is underway. We will present an update of the current status of the project and highlight the field and laboratory methodology. We expect to see low overall invertebrate diversity across all sites but with a greater degree of spatial variation in species richness for the inshore samples, possibly related to the inflowing freshwater rivers that enter the lake in the north and western portions of the lake

Authors:

Camryn Bigelow, Southeastern Louisiana University  (camryn.bigelow@selu.edu)

Alexander Mott, Southeastern Louisiana University  (alexander.mott@selu.edu)

Kyle Piller, Southeastern Louisiana University  (kyle.piller@selu.edu)